Process and composition for preservation and improved color retention of meats



United States Patent PROCELQS AND (ZOMPGSITEGN FGR PRESERVA- TIDN ANDE'IVHROVED (ZGLQR RETENTEGN @F HEATS August R. Kohler, Trenton, N..l.,Wilbur H. Miller, Springdale, (Iona, and Harold M. Windlan, Trenton, Ni,assignors to American Cyanamid Company, Ne. York, N.Y., a corporation ofMaine No Drawing. Filed July 10, 1958, No. 747,598

8 Claims. (Cl. 9--157) This invention relates to food, its improvementand preservation. More particularly, the invention relates to thetreatment of fresh cut meat whereby its quality and appearance aremaintained over longer periods of time than would otherwise be the case.

The control of meat spoilage is a major economic problem and isimportant from the standpoint of public health. Fresh cut meat displayedin retail outlets are subject to rapid bacterial spoilage and colordeterioration. Fresh meats especially when pre-packaged require anenvironment of relatively high humidity in order to preserve a goodcolor appearance. If the humidity is too low, rapid surface drying isenhanced with accompanying browning or darkening of the exposedsurfaces. On the other hand, subjection of the surfaces of meat tomoisture enhances the opportunity for microorganisms to multiplyrapidly, thereby increasing the danger of spoilage. Further, it isvirtually impossible under the usual conditions for handling, preparingand displaying prepackaged fresh meats to prevent contamination of thesurfaces of the meat with a multitude of microorganisms. As a result, ithas usually been considered necessary to keep meat under refrigerationin large wholesale cuts for cutting and packaging at the retail outlet.

Obviously, from a commercial standpoint adequate means for controllingmicrobial spoilage and color loss of fresh cut meats for longer periodsof time than have heretofore been obtained would be highly desirable. Itwould permit delivery of consumer packaged meat instead of quarters orhalves of carcasses thereby resulting in greater economy, better andmore centralized quality control as well as less waste in terms oftrimming losses. Furthermore, deterioration of meat in transit would becurtailed whereby meat with a longer shelf life would reach the ultimateconsumer.

In view of the success of antibiotics in controlling the growth of manyorganisms, considerable attention has been directed toward the use ofantibiotics for controlling meat spoilage. Various investigations haveshown that when antibiotics, particularly the broad-spectrum antibioticssuch as chlortetracycline, oxytetracycline and tetracycline, wereapplied to the surfaces of fresh meat, bacterial growth was inhibited.Further observations revealed that the shelf life of the meat so-treatedwas extended for several days.

Unfortunately, the shelf life of pre-packaged cut meat is still not aslong as desired and spoilage comes sooner than is desired. Also, thereis a rapid deterioration of the bright red color of most cut meat whichmakes the meat undesirable to prospective consumers, even though themeat might still be suflicierrtly free from pathogenic microorganisms asto be safely edible. Sometimes the texture and odor of fresh cut meatdeteriorates even though the meat may not be sufficiently spoiled to beinedible.

We have now discovered that we can enhance the refrigerated shelf lifeand organoleptic properties of color, odor and texture of fresh cut meatproducts without impairing its flavor for considerable periods of timeby the conjoint application of an antibiotic of the type and kind to bemore particularly described hereinafter and nystatin or myprozine from0.5 to parts per million based on the weight of the meat.

The antibiotics that may be used to advantage in practicing the presentinvention should have as wide a bacterial spectrum as possible and beable to inhibit the growth of the bacteria that are generallyencountered in spoiled meat. The antibiotic should be relatively stableunder conditions found in meat, non-toxic and not adversely affect thecolor or taste. The antibiotic should also be water soluble to theextent that the quantities which are necessary for treatment can beapplied in the form of an aqueous solution if desired.

Preferred antibiotics for use in the present invention are those of thetetracycline series, including chlortetracycline, bromotetracycline,oxytetracycline and tetracycline itself. Of these, chlortetracyclineapears to have the most desirable properties. Other wide-spectrumantibiotics such as chloramphenicol may also be used to practice theinvention. These antibiotics may be used in any of their water-solubleforms, usually as a mineral acid salt such as the hydrochloride.However, various other metallic salts such as the alkaline earth metalsalts and the alkali metal salts may be used. Water-soluble complexessuch as the borate or phosphate may also be used if desired.

In carrying out the present invention, an aqueous solution orsubstantially dry powder containing the antibiotic and either nystatinor myprozine is first prepared. Although no adjustment of the pH of thesolution is necessary, it is possible, if desired, to stabilize thesolution with suitable bufiering agents. The solution or dry powder isthen applied to the exposed surface of the cut meat at about 4050 F.Although application at ordinary room temperature is possible, we preferthat the treatment of the cut meat be carried out between 40-5 0 F. inorder to minimize the possibility of an onset of bacterial developmentwhich may occur at ordinary room temperature. Application of thesolution may be done by instantaneously dipping the exposed surfaces ofthe cut meat in the solution or, if desired, the solution can be sprayedon the exposed surfaces of the meat utilizing any mechanical sprayers,hand atomizers, or the like. Application may also be made to the exposedsurfaces of the meat either mechanically or by hand using asubstantially dry powder mix containing the antibiotic and eithernystatin or myprozine. However, in using the dry powder method ofapplication, it is necessary that a bulk carrier be added in order toeffectuate an even distribution of the dry powder comprising theantibiotic together with nystatin or my-prozine over all the exposedsurfaces of the meat.

The carrier employed may be common salt, flour salt, which is a finelydivided form of common salt, monosodium glutamate, starch, glucose andthe like. The preferred carrier is common salt, although any ediblepowdered material which is inert to the meat and the antiiotic may beused.

If application is made by dipping or spraying, it is desirable to allowthe cut meat so treated to drain for five to sixty minutes to remove theexcess solution.

Following the treatment of the meat as described, the meat is then traypacked or placed on backing boar overwrapped in a suitable heat-scalableflexible film as, for example, polyethylene, coated cellophane, or thelike and stored under refrigeration at about 35-40" F.

The amount of broad-spectrum antibiotic applied to the fresh cut meatshould be from about 0.5 to 100 parts per million of the antibiotic,chlortetracycline, oxytetracycline, tetracycline, etc., based on theweight of the meat. This may be achieved by dipping the meat in anaqueous solution containing from about 10 parts to 1000 parts by weightof the antibiotic, or by spraying such a solution on the meat. Whenthe'antibiotic is applied by dusting a powder on its surface, the drypowder may contain from about .05 to about 10 percent by Weight of theantibiotic.

The othe active components of the treating composition, nystatin ormyprozine, should be present so that from 0.5 part by weight to 500parts by weight of these should be retained on the meat as a result ofthe treatment. The aqueous solution in which the meat is should,therefore, contain about 10 parts to 1000 parts by weight of nystatinor. myprozine. If these two agents are applied as a dry powder with theantibiotic, the powder should contain 0.05 percent to 10 percent byweight of these. 7

Nystatin and a method of producing it are disclosed in United StatesPatent No. 2,797,183 to E. L. Hazen et a issued June 25, 1957. Myprozineis described United States application Serial No. 599,394, filed byEdward 3. Backus et al. on June 23, 1956. The product i produced bycultivating culture A5283 under submerged aerobic conditions in anaqueous nutrient medium containing an assimilable source ofcarbohydrate, nitrogen and inorganic salts.

We have found that the conjoint application of an antibiotic asdescribed herein and either nystatin or myprozine gave results notforeseeable from the work previously reported in the prior art. We foundthat in treating fresh out meat with such combinations,a synergisticaction was obtained resulting in both the extension of the refrigeratedshelf life and retention'of good 'orgzmoleptic properties of the freshcut meat so treated for longer periods of time than has heretofore beenaccomplished.

The meat used in carrying out this invention was obtained from variouswholesale outlets as hind and tore quarters and cut to approximately thesame size as is EXAMPLE 1 Fresh bonelesschuck was cut into approximatelyone inch cubes. The meat samples were divided into four groupshavingabout samples per group. Group I represents unheated meat andcorresponds to the control. Group II represents meat treated with 3parts per million ohlortetracycline hydrochloridein substantially drypowder form homogeneously dispersed in flour salt. III represents'meattreated with a substantially dry powder mixture containing 3 parts permillion chlortetracycline hydrochloride and parts per million nystatinhomogeneously dispersed in flour salt. Group IV represents meat treatedwith 'a substantially dry powder mixture containing 3 parts per millionchlortetracycline hydrochloride and 10 parts per million myprozinehomogeneously dispersed in flour salt. The powder used to dust the cutmeat contained approximately '.15% by.

by weight nystatin resistant coated cellophane and stored underrefrigeration at about 36 F. for the duration of the experiment. Sam-Group.

ples were removed periodically from each group and microorganism countwere made. Observations were made of the color and general appearance ofthe samples. Samples for bacterial counts were prepared by homogenizingthe sample of meat in -a sterile blender containing sterile distilledwater in an amount equal to three times the weight of the meat for threeto five minutes.

Based on the microorganism count and appearance, it Was determined whenthe meat would be considered spoiled, that is to say unacceptable forconsumer use and discolored when the change in. color was suthcient torender the meat unacceptable for human use. Table 1 shows the number ofdays before spoilage and discoloration took place. In the case ofspoilage, the test was not continued beyond the twenty-second day atwhich point the microorganism count was still within acceptable limits.This is indicated by the plus mark after the day number.

Table 1 Group Treatment before storage spoilage, Discoloradays tion,days I Control (untreated) 7 5 II Ohlortetracyeline hydrochloride 3 1113 p.p.m. III- Ohlortetracycliue hydrochloride 3 22+ 20 p.p.m. plus 10p.p.m. Nystatin. I\ Ohlortetracycliue hydrochloride 3 22+ 22 p.p.m. plus10 ppm. Myprozine.

The results of Table 1 show that when beehchuck was 'treated withcombinations of chlortetracycline hydrochloride-nystatin andchlortetracycline hydrochloridemypro- Zine, an increase in shelf life ofat least 15 and 11 days was respectively obtained over untreated meatand meat treated with chlortetracycline hydrochloride alone. It is alsoshown that good color appearance of the meat was maintained 15 to 17days longer than the control and 7 to 9 days longer than the meattreated with chlortctracycline hydrochloride alone.

EXAMPLE 2 The procedure of Example 1 was repeated usingfresh bonelessbeef chuck. In this series of experiments group I represents untreatedmeat. Groups II and III represent meat treated with 3 and 10 ppm.respectively of sub-' stantially dry powdered nystatin homogeneouslydispersed in flour salt. Groups IV and V correspond to groups III and IVof Example 1. The data obtained are shown in Table 2.

Table 2 Group Treatment before storage spoilage, V Discoloradays tion,days 7 I Control (untreated) 6 4 IL-.. Nystatin3 p.p.1n V 8 8 III--.Nystatiu-l0 p.p.m 8 6 IV Chlortetracycline' hydrochloride 3 15 14 p.p.m.plus 3 ppm. Nystatin. V Ohlortetracycline hydrochloride 3 15 14 p.p.m.plus 10 ppm. Nystatin.

The results of the table show that when beef chuck was treated withcombinations of chlortetra'cycline hydro .chloride and nystatin, anincrease in shelf life of 7 to 9 EXAMPLE 3 The procedure-of Example 1was repeated using fresh pork loin. The meat samples were divided intofive groups as described in Example 2. The results are shown in Table 3.

EXAMPLE 4 Example 3 was repeated except that the application of the drypowder mixtures to the exposed surfaces of the meat were carried out atthe rate of 6 grams per kilogram of meat. The results are shown in Table4.

Table 4 Group Treatment before storage spoilage, Discoloradays tion,days I--- Control (untreated) l 15 7 II- Nystatin3 p.p.m l6 7 I11".Nystatin p.p.m.-. 16 7 IV Chlortetracycline hydro 20 p.p.m. plus 3p.p.m. Nystatin. V Chlortetracycline hydrochloride 3 20+ p.p.m. plus 10p.p.m. Nystatin.

EXAMPLE 5 Fresh boneless beef chuck was cut into approximately one inchcubes. The meat samples were divided into four groups having 5 samplesper group. Group I represents untreated meat. Group II represents meattreated with an aqueous solution containing 3 parts per millionchlortetracycline hydrochloride. Group 111 represents meat treated withan aqueous solution containing 3 parts per million chlortetracyclinehydrochloride and 10 parts per million nystatin. Group IV representsmeat treated with an aqueous solution containing 3 parts per millionchlortetracycline hydrochloride and 10 parts per mihion myprozine.

The treatment was carried out by spraying the solutions containing thedesired combinations on the exposed surfaces of the meat at the rate of2 milliliters per kilogram of meat using a De Vilbis hand atomizer. Therest of the procedure was the same as described in Example 1.

The results obtained are shown in Table 5.

The results of Table 5 further illustrate that when the meat was treatedwith combinations of chlortetracycline hydrochloride and either nystatinor myprozine a pronounced increase in shelf life and maintenance of agood color appearance was achieved over untreated meat and meatsimilarly treated with chlortetracycline hydrochloride alone.

EXAMPLE 6 Fresh beef round steak was cut into portions of about inchthickness and Weighing approximately one pound. The meat samples weredivided into two groups having about 5 samples per group. Group 1represents untreated meat and group II represents meat treated with asubstantially dry powder mixture containing 3 parts per millionchlortetracycline hydrochloride and 10 parts per million myprozinehomogeneously dispersed in flour salt.

The rest of the procedure is the same as described in Example l.

The results obtained are shown in TABLE 6.

Table 6 Group Treatment before storage spoilage, Discoloradays tion,days I Control (untreated) l1 8 IL--. Chlortetracycline hydrochloride 3p.p.m. plus 10 p.p.rn. Myprozine- 18 16 EXAMPLE 7 The procedure was thesame as in Example 6 except that the spray method of application wasused as shown in Example 5. In this example, group 1 representsuntreated meat and group 11 represents meat treated with an aqueoussolution containing parts per million chlortetracycline hydrochlorideand 500 parts per million myprozine.

The results obtained are shown in Table 7.

Table 7 Discoloration, days Treatment before storage spoilage,

days

MAMPLE 8 Fresh beef round steak was cut into portions of about inchthickness and weighing approximately one pound. The meat samples weredivided into two groups having about 5 samples per group. Group Irepresents untreated meat and group I1 represents meat treated with anaqueous solution containing 20 parts per million chlortetracyclinehydrochloride and 100 parts per million myprozine.

The treatment was cairied out by instantaneously dipping the meat in afour gallon vessel containing the solution of the desired concentration,drained for 5 to 10 minutes to remove any excess solution, placed onbacking board, overwrapped with cellophane and stored at 36 F. for theduration of the experiment. The rest of the procedure is the same asshown in Example 1.

The results obtained are shown in Table 8.

Table 8 Discoloration, days Treatment before storage spoilage,

days

Control (untreated) Chlortetracycline hydrochloride 20 p.p.m. plus 100p.p.m. myprozine.-

In the examples, nystatin and myprozine are shown as the only addedmaterials in each formulation. They are, of course, equally effective ifa mixture is used but ordinarily this does not present any importantadvantage. The invention, however, includes the use of mixtures.

We claim:

1. A method of preserving the quality and appearance of fresh cut meatwhich comprises contacting the surface of fresh cut meat with a solutioncontaining from 0.5 to 100 ppm. of a broad-spectrum antibiotic andmyprozine in amounts from 0.5 to 500 p.p.m. the amounts of bothantibiotic and myprozine being based on the weight of the meat.

2. A process in accordance with claim 1 in which the antibiotic ischlortetracycline.

3. A method of maintaining the quality and appearance of fresh cut meatwhich comprises the step of immersing a cut of fresh meat in an aqueoussolution containing 10 parts to 1000 par-ts by weight of abroad-spectrum antibiotic of the group consisting of chlortetracycline,tetracycline, oxytetracycline and chloramphenicol and from 10 parts to1000 parts by Weight of myprozine.

4. A methodof preserving the quality and appearance of fresh cut meatwhich comprises the step of dusting over the freshly cut surface thereof'a powder comprising an inert carrier and from .05 percent to 10percent'of a 5 broad-spectrum antibiotic of the group consisting ofchlortetracycline, tetracycline, oxytetracycline and chloramphenicol and0.05 percent to 10 percent by weight of myprozine. 7

'5. A composition, of matter ,for the preservation'of fresh cut meatwhich comprises a mixture of an inert carrier and .05 percent to 10percent by weight of a broad-spectrum antibiotic of the group consistingof chlortetracycline, tetracycline, city-tetracycline andchloramphenicoland .05 percent to 10 percent by Weight of myprozine. r w

6, A composition in accordance with claim 5 in which the inert carrieris Water. r

' 7. A composition in accordance with claim 5 in which the inertcarrieris finely divided sodium chloride.

8. A composition of matter in accordance with claim 5 in which thecomposition of matter is in a finely powderedform suitable for dusting.

spews-1 References {Zited iri the file of this patent UNITED STATESPATENTS 2,944,907 Paganq et al. July 12, 1960 oTHEn REFERENCES FoodTechnology, April 1953, pp. 165 and 166, article entitled The Useof'Antibiotics in Preservation of Fresh Beef, by Goldberg et a1.

Antibiotic Symposium, October 1957, Paper No. 101 by A. P. Struyket.31., article entitled Pimaricin, a New Antibiotic. 7

Applied Microbiology, March 1954, pp. 88-94, inclusive, article entitledThe Use of Antibiotics in Meat Processing, by H. H. Weiser et 21.

Food Technology, October 1958, ,pp. 562-567, inclusive, article entitledMaintaining Freshness of Berries Using Selected Packaging Materials andAntifungal Agents, by I. C. Ayres et a1.

1. A METHOD OF PRESERVING THE QUALITY AND APPEARANCE OF FRESH CUT MEAT WHICH COMPRISES CONTACTING THE SURFACE OF FRESH CUT MEAT WITH A SOLUTION CONTAINING FROM 0.5 TO 100 P.P.M. OF A BROAD-SPECTRUM ANTIBIOTIC AND MYPROZINE IN AMOUNTS FROM 0.5 TO 500 P.P.M. THE AMOUNTS OF BOTH ANTIBIOTIC AND MYPROZINE BEING BASED ON THE WEIGHT OF THE MEAT. 